通风方式对厨余垃圾堆肥H_2S和NH_3排放的影响

为减少厨余垃圾堆肥过程中恶臭物质的排放,设计通风方式对H_2S和NH_3排放影响的进行研究。厨余垃圾和玉米秸秆按照湿基比例85∶15进行充分混合后作为堆肥原料,堆肥试验在100-L的密闭发酵罐中进行,堆肥周期为30d。堆肥试验分别设置2.2(T1,持续通风)、3.3(T2,通风40min,停20min)和6.6m~3/(m~3·h)(T3,通风20min,停40min)3种通风方式。结果表明:3个堆肥处理均满足无害化和堆肥腐熟的要求;在总通风量相同的情况下,间歇通风方式有利于降低H_2S排放,但是过大的通风量会增加堆肥过程中的总硫损失;通风量对NH_3的排放影响较大,通风量越大,NH_3的排放量越高,通风方式对NH_3的排放几乎没有影响。综合堆肥的无害化指标、H_2S和NH_3的排放以及最终堆肥产品的品质,本试验条件下通风量为3.3m3/(m3·h)的间歇通风方式既能有效控制H_2S和NH_3的排放,减少N和S营养元素损失,又能满足堆肥的无害化和堆肥产品的腐熟。

Effect of ventilation mode on H2S and NH3 emissions during kitchen waste composting

In order to reduce odor substances emissions during kitchen waste composting process,experiments were designed to investigate the effects of ventilation mode on H₂S and NH₃ emissions.Aerobic composting of kitchen waste and cornstalks was conducted at a ratio of 85:15(wet weight basis)in 100-L reactors for 30 days.The gas emissions were analyzed with a force aeration at rates of 2.2(T1,continuous ventilation),3.3(T2,run 40 min and stop 20 min) and 6.6(T3,run 20 min and stop 30 min)m³/(m³·h),respectively.The results showed all compost products met with national sanitation standard and reached maturity according to composting temperature.In the case of the same total air volume for three treatments,intermittent ventilation was beneficial to reduce H₂S emission,but excessive ventilation increased the total sulfur loss during composting process.The NH₃ emission reduced as the ventilation decreased,and ventilation mode had little effect on NH₃ emission.Taking comprehensive consideration of non-hazard index,H₂S and NH₃ emissions,and compost quality,the ventilation mode of 3.3 m³/(m³·h)(run 40 min and stop 20 min) was recommended to be applied to control H₂S and NH₃ emissions during kitchen waste composting process.